GE P444

Application Notes
P44x/EN AP/Hb
6
MiCOM P40 Agile P442, P444
(AP) 5-
5
4.6.1 Setting guidelines 100
4.6.2 Setting example 101
4.7 Directional and non-directional earth fault protection 101
4.7.1 Setting guidelines 101
4.7.2 Directional Earth Fault Protection (DEF) 102
4.8 Aided Directional Earth Fault (DEF) 103
4.8.1 DEF Protection Against High Resistance Earth Faults 103
4.8.2 Tripping Logic 104
4.8.3 Aided Directional Earth Fault (DEF) protection schemes 105
4.9 Thermal overload 110
4.9.1 Time constant characteristic 111
4.10 Residual overvoltage protection 112
4.11 Undercurrent protection 114
4.12 Voltage protection 115
4.13 Frequency protection 115
4.13.1 Underfrequency protection 115
4.13.2 Overfrequency protection 116
4.14 Circuit breaker fail protection 116
4.14.1 Typical settings 117
4.14.2 Breaker Failure Protection Configurations 117
4.14.3 Reset Mechanisms for Breaker Fail Time-Delays 119
5 NON PROTECTION FUNCTIONS 121
5.1 Circuit breaker condition monitoring 121
5.1.1 Circuit Breaker Condition Monitoring Features 121
5.1.2 CB condition monitoring 121
5.2 Circuit Breaker Control 124
5.2.1 Logic Inputs / outputs used by the CB Control logic 126
5.3 CT and VT ratio 127
5.3.1 CT Ratios 127
5.3.2 VT Ratios 128
5.4 Opto inputs configuration 128
5.5 HOTKEYS / Control inputs 128
5.5.1 Control inputs 128
5.5.2 Control I/P Configuration 129
5.5.3 Control I/P Labels 129
5.6 InterMiCOM Teleprotection 129
5.6.1 Protection Signalling 129
5.6.2 Functional Assignment 133
5.6.3 InterMiCOM Settings 133
5.6.4 Testing InterMiCOM Teleprotection 134
5.7 Programmable function keys and tricolour LEDs (“Function key” menu) 135
5.8 Supervision 136